1. Field of the Invention
The present invention concerns an imaging method on optical disks by inkjet appropriate for label printing of optical disks such as CD, CD-ROM, VCD, CD-R, CD-RW, DVD, DVD-R, DVD-RW, DVD-RAM, DVR or others.
2. Description of the Prior Art
The following three systems exist mainly for the imaging method for optical disks used actually.
(1) Screen printing method
(2) Offset printing method
(3) Inkjet printer method
There are various kinds of optical disk, such as CD, CD-ROM, VCD, CD-R, CD-RW, DVD, DVD-R, DVD-RW, DVD-RAM, DVR or others, and all of the aforementioned media require the label printing.
Actually, the most used printing method is (1) screen printing. The reason is that, in case of printing letters or others, the definition is better than the other methods and the printing method is relatively simple. However, this method is not appropriate for graphic (color) printing.
The next most used method is (2) offset printing. This method is excellent in the graphic (color) printing which is not satisfactory in (1) screen printing, and used often for VCD and DVD.
(3) Inkjet printer method is used mainly for imaging on optical disks of small quantity. The reason is that this method is more advantageous than (1) and (2) in respect of cost because a film necessary for printing and a printing plate are not required. However, as weak point of this method, it is not appropriate for mass production, because its printing speed is extremely lower than the other methods.
Actually, in optical disk production factories where a quantity of disks should be produced at a low cost, (1) screen printing and (2) offset printing are used for label printing, because of the aforementioned reasons. However, in case of these printing methods, said film and plate are essential. In addition, each time the type (label) is modified, quantities of dummy disks (to be rejected) are required for register (positioning) and color tone matching.
As most optical disks are produced by the large item small volume production, a novel imaging method allowing to solve the aforementioned problems is desired.
In addition, it is required to colorize the label printing on the optical disk and, moreover, some designs require the combination of color images and the ground white printing. Consequently, the novel imaging method should be a one that resolves all of the aforementioned problems.
In view of problems mentioned above, the present invention has a first object of providing an imaging method on optical disks by inkjet, capable of performing the imaging efficiently on optical disks by improving the problem of low processing speed during the imaging by inkjet and appropriate for the large item small volume production.
A second object of the present invention is to provide an imaging method on optical disks by inkjet, appropriate for coloring the label printing design and, moreover, facilitating the combination of color images and ground white printing.
The other objects as well as new features of the present invention are described in embodiments mentioned below.
According to the present invention, the imaging method on optical disks by inkjet comprises a white ground printing step for printing a white ground on an optical disk, and a drawing step for imaging respectively by an inkjet printer on a plurality of optical disks arranged in a line after the white ground printing step, in the drawing step, a printer head of the inkjet printer to be scanned in the linear arrangement direction of the disks and all of the linearly arranged disks to be contained in a scanning range of the head at a single time.